Preventing reposts isn't something the admins should have to deal with, that should depend on the rules of the subreddit. If you want to avoid reposts, unsubscribe from the default subreddits and find some that focus on it instead.

Are you an admin? I thought that their job was to make the as good as it can be. This includes establishing filters and bots to improve adherence to site/subreddit rules thereby improving the overall quality of content. For example, if you submit to /r/bestof with a link to a submission rather than a comment, a bot will delete your post and notify you. How is an antirepost mechanism any different in spirit?

Yes, people should know and follow the rules, but they do not. Almost every serious redditor will agree that reposting is a big issue/annoyance. My idea is for a simple filter to help diminish the issue.

I have heard the arguments about reposting having its place. Not every user sees something the first time it is posted. However, a statute of limitations that restricted the frequency of reposting could be enforced with my idea, which would be an improvement. I would also not restrict cross posting as long as the orignal was given credit.

I am already a avid member of many smaller subreddits notably /r/KarmaCourt, which concerns itself with the prosecution of members who break rules such as reposting. However, I still think that some of the best and most interesting posts come from default subs. Unsubscribing from them all would seriously diminish my enjoyment of the site.

a bot will delete your post and notify you. How is an antirepost mechanism any different in spirit?

That's not an "anti-repost" measure; the bot removed a post that broke the sub reddit rules.

I'm going to try to put this as simply as possible;

The admins will NOT implement anything site-wide that would limit the ability of the average user to submit content.

Outside of illegal content such as child porn and posting of personal information, the admins are very hands-off when it comes to content. The policing of content of each sub reddit is the responsibility of the moderators of said sub reddits.

If you would like a change to an individual sub reddit's reposting time limit, please contact the individual sub reddit in question.

Haven't seen anyone in this thread supporting it being part of the reddit core. I agree, there should be an anti-repost feature, but not as the core functionality of Reddit. It should be a bot run by the subreddit owner, or by an add-on (as suggested by psYberspRe4Dd). Having it built into Reddit adds additional load onto their servers, which would make Reddit slower than it already is. It makes much more sense to have a bot do the checking and then delete if necessary because people are willing to run those bots.

[Please don't] complain about reposts. Just because you have seen it before doesn't mean everyone has. Votes indicate the popularity of a post, so just vote. Keep in mind that linking to previous posts is not automatically a complaint; it is information. Votes indicate how the community values information, so just vote.

/r/pics and the other major subreddits will never disallow reposts because new members would get annoyed for their posts getting deleted.

Regarding your example earlier:

For example, if you submit to /r/bestof[1] with a link to a submission rather than a comment, a bot will delete your post and notify you. How is an antirepost mechanism any different in spirit?

That is a moderator run feature, not done by the admins or anybody else. One of the mods has the bot set up running on their home computer. It's different because you're suggesting that the admins run bots to scan all reddit posts, instead of moderators taking care of their own subreddit.

Almost every serious redditor will agree that reposting is a big issue/annoyance.

"Serious" redditors exist?

I'm on here a lot, but I wouldn't say I'm a "serious redditor".
I don't mind reposts, because sometimes the post still makes me laugh. The only reposts I hate are when it's been submitted a few times in the same day, and when the submitter claims someone else's story as their own.

Just because it's a repost to you, it doesn't mean it's a repost to other users. If reposts were banned site-wide then there'd be very little content remaining.

Yap thought about that too but I guess that probably would be a feature of Reddit Enhancement Suite so gonna make a post in /r/Enhancement. Thought about the thing loading after you put in the url on the submit page, you can still submit the usual way.